The shape of the dental arch.

The shape of the dental arch. The shape of the dental arcade was measured in a cross-sectional study of 2,040 sets of maxillary and mandibular study casts of Caucasoids, Mongoloids, and Negroids between 4 and 20 years of age. Three methods of dental arcade analysis were used: dental arch area, dental arch index, and length of the arc of the dental arcade. Each of these computational techniques showed that a different growth pattern was shared by the three ethic groups, and important factor to be taken into consideration in orthodontic treatment.


Editorial: AAO constituent society presidents discuss current specialty issues. Part I.


Letter: Cleidocranial dysostosis.

Letter: Cleidocranial dysostosis.


Prognosis and incidence of sex chromatin in breast cancer. A preliminary report. Results of two studies, based on a total of 126 patients (prospective--76 cases and retrospective--50 cases), on the incidence of the sex chromatin in the cancerous tissue are presented. For evaluation of prognosis in the retrospective study with a five year follow up, sex chromatin incidence was correlated with other prognositc factors such as lymph node metastasis, the disease free interval of distant metastasis and the size of the tumor. Whereas positive significant correlation between sex chromatin incidence and a five year survival time or disease free interval of distant metastasis was observed, no correlation was seen between sex chromatin counts and lymph node metastasis or the size of the tumor.


Rhythmic variation of sex chromatin and glucose of phosphate dehydrogenase activity in human oral mucosa during the menstrual cycle.


Correlation of in vitro immune response with clinical course of malignant neoplasia in dogs. An attempt was made to quantify the host antitumor immune response in 16 dogs with progressively growing tumors by evaluating the in vitro reactivity of their lymph node or peripheral blood lymphocytes to their own tumor cells. Serum from dogs with the same histologic type of neoplasm inhibited allogenic lymphocyte cytotoxicity, whereas serum from normal dogs, and a dog clinically free of osteosarcoma 17 months after limb amputation, did not significantly block cell-mediated reactivity. Low ratios of sensitized lymphocytes to tumor cells often stimulated tumor cell growth in vitro. Autologous serum from dogs with progressively growing neoplasms appeared to potentiate the stimulation of tumor growth above a simple blocking of lymphocyte-mediated cytotoxicity. An attempt was made to correlate the in vitro immune reactivity of the dog to the clinical behavior of its neoplasm. There was fair to good correlation in 12 dogs and no correlation in the remaining 4 dogs.


X-ray and fine-needle biopsy in diagnosis of non-palpable breast lesions. Using mammography and xeroradiography among 78 patients with non-palpable breast lesions, three cases of suspected carcinoma were detected. The diagnosis was confirmed by cytology after x-ray guidance of the fine-needle biopsy.


Infection prevention in acute nonlymphocytic leukemia. Laminar air flow room reverse isolation with oral, nonabsorbable antibiotic prophylaxis. Reverse isolation and prophylactic oral nonabsorbable antibiotics were evaluated among 64 consecutive noninfected adults with acute nonlymphocytic leukemia admitted for remission induction. Patients were randomly allocated to laminar air flow room reverse isolation with oral nonabsorbable antibiotics (LAF plus A), routine hospital ward care with antibiotics (W plus A), or ward care alone (W). The LAF plus A patients had a significantly decreased incidence of total infection, bacteremias, pneumonias, rectal abscesses, urinary tract infection, and pharyngitis. Infectious deaths were reduced in the LAF plus A group and the time to the first infection or to fatal infection was delayed. The W plus A patients who regularly ingested the antibiotics had a reduction in infections similar to that of the LAF plus A patients but those who could not tolerate the antibiotics had an incidence of infection comparable to the ward patients. The LAF plus A and the W plus A patients also had higher complete remission rates and longer median survival than the unprotected ward patients.


Investigation of single-exposure microwave ocular effects at 3000 MHz.


Possible physical substrates for the interaction of electromagnetic fields with biologic membranes. A quantized electrochemical model of a greater membrane concept that comprises the neuronal phospholipid sheet of the plasma membrane and the constituents of the intercellular spaces in brain tissue is proposed as a basis to explain several recent experimental results that concern the interaction of electromagnetic fields with the central nervous system. These fields consist of gradients far below those needed for direct intervention with action potentials or chemical transmitters at synaptic sites. Problems associated with the rectification of modulated signals and transduction into brain tissue are also briefly considered.


Use of a dielectric lens for experimental microwave irradiation of the eye.


Screening for cataracts among veteran radar repair and maintenance technicians.


Introduction: Effects of electromagnetic radiation on the nervous system.


The ocular effects of microwaves on hypothermic rabbits: a study of microwave cataractogenic mechanisms. Rabbits, irradiated by known cataractogenic levels of 2.45 GHz radiation at 5 cm, did not develop cataracts if kept under general hypothermia. Radiation-induced temperature elevation appears to be essential for the cataractogenic effect of microwaves.


Ultrastructural changes in the rabbit lens induced by microwave radiation. Rabbits were irradiated with 2450-MHz continuous microwave energy. Effects of the radiation on the ocular lens were assessed by slit-lamp biomicroscopic examination of the eye. Two lenses were selected for electron microscopy, one that was severely damaged and one that appeared unaffected by the radiation. There were prominent ultrastructural changes in both lenses.


Ascorbic acid changes in cultured rabbit lenses after microwave irradiation. Whole body exposure of rabbits to microwave radiation causes a decrease in ascorbic acid in the lens. In our study, rabbit lenses maintained in culture medium (37 degrees C) were exposed to either pulsed or continuous wave S-band radiation for 10-15 min at power densities between 0 and 200 mW/cm-2. Total ascorbic acid was measured in selected lenses 1-3 days after irradiation. The temperature of the culture medium was measured during irradiation. Matched control lenses were exposed to similar time-temperature environments, but without microwave irradiation. Ascorbic acid decreased significantly in lenses exposed to microwave radiation. No differences were found, however, between irradiated and control lenses subjected to identical time-temperature conditions. At a given average power density, the time-temperature variation was independent of modulation. A decrease in ascorbic acid is apparently a direct thermal effect of microwave radiation in rabbit lens culture.


Microwave-induced acoustic effects in mammalian auditory systems and physical materials.


Biochemical and neuroendocrine aspects of exposure to microwaves.


Action of Corti's organ and the cochlea: a new theory. An "engineer's model" of the labyrinth is derived from the monoclinic crystal and the avian egg. The anatomy of the human cochlea and of the semicircular canals is then related by diffraction theory and Fresnel's explanation of optic activity. Increased cochlear electric potential, which represents stored energy, is associated with mechanical translation of the basilar membrane and angular separation of Corti's rods and is effected by "pumping" by the endolymphatic sac and the muscles that act on the auditory ossicles. The semicircular canals function as valves; the utricular and saccular macules form holograms and reflect the energy into the cochlear duct. Incoming acoustic waves excite dipole resonance and stimulate emission of a fraction of the stored energy; further amplification is effected by the hair cells, which, together with the tectorial membrane, behave like a transistor. These findings lead to a new theory of static balance and the action of Corti's organ: the labyrinth functions as a traveling wave maser of which the cochlea is the slow wave structure. Cochlear geometry itself effects resolution of incoming sound pitch. Corti's organ corresponds to the melatopes of the crystal, and the inter-rod angle is critical for any particular frequency, since it is related to dispersion of the optic axes.


The effect of microwaves (2450 MHz) on isolated rat liver mitochondria.


A comparison of thermal and radio-frequency exposure effects on trace metal content of bloof plasma and liver cell fractions of rodents.


Effects of microwave radiation of enzymes.


Acute staphylococcal infections in rabbits irradiated with 3-GHz microwaves.


Discussion paper: Irradiation of bovine serum albumin with a crossed-beam exposure-detection system.


Effects of electromagnetic radiation on implantation and intrauterine development of the rat.


Threshold effects of microwave radiation on embryo cell systems.


Effects of electromagnetic fields on fecundity in the chicken. Egg production was reduced when young laying hens were kept in contact with metal cages while being continuously exposed to the following cw fields: a vhf field at a frequency of 260 MHz, with an incident power that decreased from 100 to 4mW during the experiment; a uhf field at a frequency of 915 MHz, with an incident power of 800 mW during the first 2.5 weeks, zero during the following week, and 200 mW for the remainder of the experiment; a uhf field at 2.435 GHz, with an incident power of 800 mW; an elf electric field at a frequency of 60 Hz, with a calculated value of field strength of 1600 V/m; an elf magnetic field at 60 Hz, with a value of magnetic flux density of 1.4G. With the exception of the hens exposed to the uhf field at 915 MHz, all other treated groups laid significantly less eggs than the controls (p smaller than or equal to 0.01). This reduction (similar 15% less than the controls) began with the first 4-week production period. The egg production curves for the hens exposed to the vhf field at 260 MHz and to the uhf field at 2.435 GHz were approximately the same beginning with the sixth week of production, and they maintained comparable production levels for the remainder of the experiment. An 8% total drop in production also was experienced in the group of birds exposed to the 915-MHz field, which pulsed because of equipment failure. Egg production rate curves for the birds in the elf electric and magnetic fields were substantially different from those exhibited by birds in the other electromagnetic fields. The birds in the E-field regained a production level comparable to the controls after 11 weeks production, whereas those in the B-field dropped to 31% production, which was approximately 40% poorer than the controls by the twelfth week of production. Fertility of cocks and hens was not affected by continuous low-power vhf and uhf near-zone electromagnetic exposure or elf electric or magnetic field treatment. Fertility was exceptionally good, except for the controls and the hens exposed to the elf electric field. The hatchs of fertile and of total eggs were not significantly influenced by exposure to any of the five fields. A considerably lower incidence of male chicks was noted in the elf magnetic field treatment (32.3%). The sex ratio in the other groups appeared to be relatively normal. No macroscopic abnormalities attributable to treatments were noted in the chicks hatched or in the dead embryos.


Microwave dose-response relationships on two behavioral tasks.


Some effects of exposure of the Japanese quail embryo to 2.45-GHz microwave radiation. Exposure of quail eggs 4 hr per day during the first 5 incubation days at 2450 MHz and in an exposure field of 30 mW/cm-2 and at an absorbed power of 14 mW/g does not cause any great change in body weight, observed gross malformations, rbc, wbc, hematocrit, hemoglobin, or differential wbc percentages. If small differences exist in these parameters due to microwave exposure, they are obscured by the large variability between individual quail. This variability is believed to partially result from changing blood values in the developing young quail, and the 2-day spread in ages at the time of sacrifice could account for some of the variability. The overall hatch percentages for the exposed and control eggs were approximately equal. A slight significant decrease (11%) in hemoglobin was noted in the birds irradiated on Day 2. Additional verification, however, is needed, because the observed change is less than the normal range of values observed in young quail. These data do suggest, however, that exposure of developing Japanese quail embryo to microwave radiation of the frequency and power density level used in this study does not preclude normal systemic development, hematologic differentiation, or the general hardiness of the hatched quail.


Preliminary investigations of the effects of low-level microwave radiation on spontaneous motor activity in rats. Male rats were irradiated with microwaves of 10.7 GHz (cw), 3 GHz (cw), or 3 GHz (pw) for 185 hr with power densities of approximately 1 mW/cm-2. Spontaneous activity was automatically measured and analyzed in five amplitude classes, after irradiation had ceased. No differences were found between the irradiated and the similarly treated nonirradiated control rats. A few rats were exposed for 17 days to 3 GHz (pw) at 25 mW/cm-2. Here, again, the spontaneous motor activity was not affected. Before irradiation, these rats had been trained to constant peak performance in a 2-m long runway. Their running times remained unchanged by this treatment regimen and did not differ from those of nonirradiated control rats. So far, no deleterious effects of the microwave radiation used has been detected.


Effects of low-level microwave radiation on behavioral baselines.


Behavioral effects of pulsed microwave radiation.


Microwave energy distribution measurements in proximity to man and other their practical application.


Effects of low-intensity microwaves on isolated neurons.


Measurements of power absorption by human phantoms immersed in radio-frequency fields.


A miniature broad-band electric field probe.


A pyroelectric probe for measurement of microwave power density under far-field conditions.


Discussion paper: Fiberoptic liquid crystal probe for absorbed radio-frequency power and temperature measurement in tissue during irradiation.


Discussion paper: Strong dependence of whole animal absorption on polarization and frequency or radio-frequency energy. A two-plate stripline is used to determine wide-band radio-frequency (285-4000 MHz) absorption characteristics of 96-390-g rats and brain-phantom prolate spheroidal bodies. The results compare well to those for free space irradiation. At resonance, for E along the long dimension (â), a power deposition nine times higher than that for the H parallel â orientation is observed. For rats in the k parallel â configuration, the frequencies of peak absorption and the maximum absorption at these values demonstrate W-1/3 and W 2/3 dependencies, respectively, upon the weight W of the animal. This finding implies that whole animal absorption is a size- and shape-dependent phenomenon.


Field measurements, absorbed dose, and biologic dosimetry of microwaves.


Future research directions and needs in biologic electromagnetic radiation research.


Overview of electromagnetic radiation research: past, present, and future.


Some effects of electromagnetic radiation on the brain and spinal cord of cats.


Effects of modulated VHF fields on the central nervous system.


Synchronization of cortical neurons by a pulsed microwave field as evidenced by spectral analysis of electrocorticograms from the white rat.


Do microwaves alter nervous system structure?


Immobilization hypercalcemia crisis.

Immobilization hypercalcemia crisis. Profound hypercalcemia associated with immobilization is rare. Hypercalcemic crisis occurring as a result of immobilization in which there was not a coexisting, contributing medical condition has not, to our knowledge, been reported previously. Failure to consider hypercalcemia as the source of progressive anorexia, nausea, vomiting, and irritability resulted in a respiratory arrest and nearly fatal outcome in the case of a 13-year-old boy one month after a simple femoral fracture. Therapy consisting of the intravenous administration of fluids and corticosteroids was successful in lowering the serum calcium level until mobilization could be accomplished. Review of previously reported cases emphasizes the difficulty in recognition and diagnosis of this unusual condition. Surgeons treating patients with fractures should be aware of this complication and familiar with its appropriate therapy.


Skin changes secondary to hydroxyurea therapy. Hydroxyurea is an effective agent in the treatment of chronic myelogenous leukemia. The toxic reactions have included myelosuppression and megaloblastosis. During long-term maintenance therapy, dermatologic alterations occurred in seven of 20 patients and consisted of partial alopecia, increased pigmentation, scalings, atrophy of the skin and subcutaneous tissues, nail changes, and erythema of the face and hands. The histologic changes were similar to those seen in lichen planus. These observations were a factor leading to the use of hydroxyurea in the treatment of psoriasis.


Azurophil and specific granules of blood neutrophils in chronic myelogenous leukemia: an ultrastructural and cytochemical analysis. That most patients with chronic myelogenous leukemia (CML) have either very low levels or no leukocyte alkaline phosphatase activity (LAP) is an established fact. In view of our new findings7 that normal mature human polymorphonuclear leukocytes (PMN) contain two types of granules, azurophils (1/3) and specifics (2/3), and that alkaline phosphatase is present only in specific granules, we undertook the present studies to determine whether these neoplastic PMN lack a specific granule population or simply lack the enzyme. The cellular buffy coats of five patients with CML (Ph1 plus, LAP minus) were fixed in glutaraldehyde, incubated for peroxidase to identify the azurophil population, and examined by electron microscopy. It was found that the specific granule population was present in all mature PMN. Counts of both azurophil and specific granules per cell were slightly lower than normal but were within an 80%-90% overlap of the normal range. We therefore conclude that the low level of LAP in patients with CML reflects a deficiency of the enzyme rather than a missing granule population. Although the mature PMN appeared relatively normal (with few exceptions), circulating myeloblasts and promyelocytes revealed several abnormalities, the most notable being the presence of large bundles of cytoplasmic microfilaments. The blood of two patients in the terminal phase of disease was reexamined. Most of their cells were immature, with aberrations similar to those in myeloblasts and promyelocytes in the chronic phase of the disorder. In addition, however, we discovered three adnormal populations of mature PMN: (1) PMN containing both populations of granules but lacking peroxidase, (2) PMN lacking specific granules, and (3) PMN lacking azurophil granules. Our findings emphasize the value of electron microscopy and cytochemistry in detecting abnormalities of maturation in the cytoplasm of leukemic PMN.


Histone abnormalities in adult acute leukemias. Arginine-rich and lysine-rich histones were extracted from various cytologic types of leukemic blasts and from preparations rich in normal monocytes. On polyacrylamide disc electrophoresis, the patterns of normal monocyte histones closely resembled those found in acute histiomonocytic leukemia (Schilling type). The electrophoretic patterns of histones obtained from leukemic blasts in acute myelomonocytic leukemia (Naegeli type) were similar to those found in both acute myelobastic leukemia and chronic granulocytic leukemia. The results support the concept that acute myelomonocytic leukemia may be closely related to, or a variant of, acute myeloblastic leukemia, and that acute histiomonocytic leukemia is most probably a monocytic rather than a myeloblastic disorder. In addition to accepted morphologic and enzymatic criteria, the present studies suggest that differences in histone patterns might be useful in further distinguishing between histiomonocytic, myeloblastic, and myelomonocytic leukemias.


Syndrome of recurrent increased secretion of antidiuretic hormone following multiple doses of vincristine. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) has been recognized to occur following treatment with vincristine. None of the reports have provided information regarding its potential for recurrence on further challenge with vincristine (VCR), an agent generally required for repeated use in patients with malignancies. Symptomatic hyponatremia and SIADH that occurred 8 days following administration of VCR in a child with acute lymphatic leukemia was documented with specific radioimmunoassay of urinary ADH levels. The further occurrence of recurrent elevations in ADH excretion 8-10 days following repeated treatment with VCR was also observed. However, SIADH was prevented by prophylactic rigorous fluid restriction. The occurrence of SIADH following VCR therefore does not preclude the further safe usage of this drug.


Interacting populations affecting proliferation of leukemic cells in culture. Peripheral blood cells from three patients with acute leukemic have been studied using a suspension culture method previously described.1 Cytogenetic studies in two of the patients permitted the identification of the proliferating cells in the cultures as being derived from a leukemic population. Cell separation studies using velocity sedimentation supported the concept that growth of the leukemic cells in culture is dependent on an interaction between two populations of leukemic cells.


Problems which inhibit the prevention of cardiovascular diseases.


The rehabilitation or habilitation of severely or profoundly retarded people.


Primary prevention and early detection in mental illness.


Prevention: problems in decision-making and implementation in mental health and mental retardation services.


Screening and prevention of high-grade mental retardation-to what purpose? Under what circumstances? On what premises?


Breaking the barriers to prevention: the role of the medical profession.


The people: motivation, education, and action.


Prevention and health maintenance revisited. Opening statement.


Fiscal and economic issues.

Fiscal and economic issues.


Health maintenance and the prevention of disability as viewed by an internist.


Prevention: the state of knowledge.

Prevention: the state of knowledge.


Screening for early detection of disease: to what purpose?


Primary prevention of heart attack.

Primary prevention of heart attack.


Primary prevention of cancer.

Primary prevention of cancer.


Health maintenance: a strategy for preventing cancer and heart disease.


Screening for early detection of cancer and heart disease.


Proceedings: The thymic hormone and cellular immunity.


Editorial: Osteosarcoma--new hope?

Editorial: Osteosarcoma--new hope?


Extramedullary involvement of the testes in childhood leukemia. Thirteen out of 163 male children with acute leukemia developed extramedullary involvement of the testes. This represented an incidence of 8.0%. These 13 children experienced 19 separate episodes of enlargement. All episodes were treated with radiotherapy. The enlargement was unilateral in 9 episodes and bilateral in 10. The bone marrow (BM) was in complete remission in 13 episodes. In 8 of 13 patients the testis was the first site of relapse since the initial BM remission. Of the males with a WBC less than 20,000/mm3 on initial diagnosis of leukemia, 4.3% developed this testicular complication, as compared to 17.0% of those with a WBC equal to or greater than 20,000/mm3. The median time interval to testicular involvement was 13 months; to death, 9 months. Relapse at other sites usually followed testicular involvement. Autopsy findings did not appear to be dose-related. Radiotherapy was clinically successful when a total dose in the range of 1200 rads was used, and is the treatment of choice for this complication.


Long-term second remissions in acute lymphatic leukemia. Long-term second remissions were seen in 5/66 patients with all. Relapse was extramedullary in 2/5. Persistent, progressive marrow lymphocytosis preceded relapse in 4/5 patients and persistent marrow eosinophilia in 1/5. All 5 patients had had an unmaintained remission of at least 6 months prior to relapse, and responded the second time to drugs which were essentially the same as those used initially. We conclude that long-term second remissions may occur in all. Patients who relapse after 6 months or more of unmaintained remission should be treated with the drugs used in current initial induction regimens in hope of cure.


Treatment of acute lymphoblastic leukemia in childreq with "prophylactic" intrathecal methotrexate and intensive systemic chemotherapy. Sventy-five children under the age of 15 years, with acute lymphoblastic leukemia, were treated with a multiple drug chemotherapy regimen (L-2) and intrathecal methodtrexate. Remission was achieved in all except 1. Three died from infection early in remission and 1 was lost to follow-up. Of the remaining 70, relapse occurred in 19; in 3 children this was confined to the central nervous system (CNS) and in 1 was in both the CNS and bone marrow. Fifty-one children continue in complete remission from 14 to 54 months. Fourteen of these children have completed 3 years of chemotherapy and are disease free 2 to 18 months posttreatment. The results indicate that periodic administration on intrathecal methotrexate with no CNA irradiation, plus intensive systemic chemotherapy, can effectively control CNA leukemia and prolong the duration of complete remissions.


The mechanism of action of methotrexate in cultured L5178Y leukemia cells. This study investigates the relationships between the methotrexate (MTX)-induced purineless state and thymineless state and between the thymineless state and the kill of L5178Y cells. As an index of the thymineless state, we measured the effect of MTX on conversion of deoxyuridylate to thymidylate. This was measured as the rate of incorporation of tritiated deoxyuridine into DNA, but it was corrected for changes in incorporation of tritiated thymidine. Thus we derived the "calculated tritiated deoxyuridine rate." During the MTX treatment, the calculated tritiated deoxyuridine rate decreased rapidly at first and then more slowly. The slow 2nd-phase block was not reversed by hypoxanthine. As the 2nd-phase block deepened, the lymphoblasts continued to die (loss of cloning ability) but recovered the ability to incorporate tritiated thymidine into DNA. After 7 hr of MTX treatment, the kinetics of the 2nd-phase block in calculated tritiated deoxyuridine rate correlated closely with the kinetics of cell kill. Thus, MTX may inhibit dihydrofolate reductase enzyme, rapidly deplete S-phase L5178Y of reduced folates, and thus produce a purineless and thymineless state. As treatment continues, MTX intensifies the thymineless state, possibly by direct inhibition of thymidylate synthetase enzyme, and the cells die predominantly a thymineless death. The purineless state initially contributes to cell kill but later does not, possibly because it partially reverses spontaneously.


Drug therapy against a transplantable guinea pig leukemia. The effects of six clinically active drugs were tested against a ttansplantable leukemia in inbred strain 2 guinea pigs. Cytoxan and 6-mercaptopurine were found to elicit a therqeutic response against this leukemia based on complete tumor regression of the established tumor as well as a substantial increase in survival time. Animals dying in the untreated control and drug-treated groups revealed typical generalized lymphoblastic leukemia. However, only Cytoxan-treated animals that had relapsed exhibited central nervous system involvement originating from the arachnoid membrane. A tow-drug combination of Cytoxan and 1-(2-chloroethyl)-3(trans-4-methylcyclohexyl)-1-nitrosourea was found not only to prevent meningeal leukemia development but also to result in "curing" all animals from their leukemia. This observation was based on a complete clinical, hematological, and histopathological "remission" period up to 176 days. The administration of 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea alone was observed not only to control the systemic leukemia but also to prevent central nervous system involvement. No relapses occurred after the first "remission" period was achieved in the groups of animals that received 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea.


Influence of fluoride on the rate of dissolution of hydroxyapatite in acidic buffer solution.


Dental caries in relation to fluoride content of enamel in the primary dentition.


In vivo microsampling of enamel fluoride concentrations after topical treatments.


Metabolism of the polysaccharides of human dental plaque. I. Dextranase activity of streptococci, and the extracellular polysaccharides synthesized from sucrose.


Desorption of protein and bacteria from hydroxyapatite by fluoride and monofluorophosphate.


Caries incidence in well-fed and malnourished rats treated with isoproterenol during development.


Accelerating monofluorophosphate uptake by hydroxyapatite.


Influence of the mineral content of enamel on caries-like lesions produced in hydroxyethyl cellulose buffer solutions.


Effect of xylitol on the growth and metabolism of Streptococcus mutans.


Participation of phosphate of bacterial origin in the phosphate exchange and rehardening of the enamel and the modifications by fluoride, chlorhexidine and propanol.


Effect of the aquired pellicle on fluoride uptake in tooth enamel in vitro.


Histological features of fluorosed human dental enamel.


Acids produced by human dental plaque metabolism in situ.


Microbial variations in approximal dental plaque.


Job preformance review scheme. 2.

Job preformance review scheme. 2.


Altered membrane sodium transport and the presence of a plasma ouabain-like inhibitory factor in acute myeloid leukaemia. 1. Sodium transport studies were performed in erythrocytes from normal subjects and from patients with acute myeloid leukaemia. Sodium influx and efflux rates were increased in erythrocytes from leukaemic patients. 2. The ouabain-sensitive component of sodium efflux was increased in leukaemic erythrocytes. 3. The high sodium efflux from leukaemic erythrocytes was decreased when the incubation media contained leukaemic plasma, suggesting the presence of an ouabain-like factor in the plasma. Paired experiments failed to show the presence of a similar factor in normal plasma. 4. Leukaemic erythrocytes showed a significantly greater ouabain uptake than the normal cells. 5. The results are discussed in relation to the wide-spread electrolyte disturbances in acute myeloid leukaemia.


Electron-probe and electron microscope studies of carious dentinal lesions with a remineralized surface layer.


Tissue conditioning and tissue conditioners.


Materials in maxillofacial prosthetics.

Materials in maxillofacial prosthetics.


Mouth protectors.

Mouth protectors.


Resins in periodontal splinting.

Resins in periodontal splinting.


General comments on continuing education. Dental education should be a continuing process from undergraduate days throughout the dentists' practising life. The development of postgraduate courses has moved earlier the point at which a licence to practise is conferred, and in so doing has increased the responsibility to pursue continuing education and training after licensure. There is a growing tendency for attendance at continuing education courses to become a condition for relicensure in the hope that this will increase the status of the profession and improve the standard of dental care. So long as the requirement is for the attendance at courses this development deserves support. However any suggestion of re-examination should be resisted since this could only lead to increased stress on the competent dentist who was a poor examinee. A questionnaire sent to dental educators produced information on the proportion of dentists currently attending continuing education courses in ten countries and also enabled the popularity of different subjects to be assessed. It is suggested that courses should be arranged so that the whole field of dentistry is covered every five years. If the profession does not organize its own programme of continuing education and motivate its members to participate voluntarily in such courses, governments may well impose upon it requirements which could be less acceptable to the status and dignity of the profession.


Resins as dental implants.

Resins as dental implants.


An economic perspective on dental practice: the economics of increasing practice size. Group dental practice is a form of organization which can show substantial professional and public benefits. Part of the support for group practice is derived from an extrapolation of the theory of economies of scale. Applied to dentistry, the theory holds that as practices grow they will be able to use their resources more efficiently than do smaller practices, and lower, thereby, the average costs of producing dental services.


Current systems of delivery of oral health services. It is suggested that in implementing, extending and redirecting systems of delivery of oral health services we should be maximizing preventive care, indirect payment and targeting for need, wheras for manpower employment and type the accent should be on selecting the best blend for the specific services to be provided, with a readiness to use constructive initiative in all areas. In associated operations research, the urgent need is for sound data on the effectiveness and efficiency of different payment systems, and on the optimal blend of private and public, professional and auxiliary manpower. What has been achieved in the delivery of oral health services over the past 50 years has been no mean  feat, but what lies ahead to be done both in developed and developing countries is a task of herculean proportions.


Serial studies of hepatitis-associated antigen and antibody in patients receiving antitumor chemotherapy for myeloproliferative and lymphoproliferative disorders. The effects of antitumor chemotherapeutic agents on hepatitis B antigen (HBAg) and antibody (HBAb) were studied serially in 25 patients with myeloproliferative and in 60 patients with lymphoproliferative disorders. HBAg was detected at some time in 17 patients, and HBAb in 40 patients. Seventeen patients who had HBAb detected immediately pretreatment had a decrease in HBAb titer which paralleled the fall in white blood cell count. In 5 of these patients, HBAg appeared when HBAb titers fell. In 3 of the 5 patients, a reappearance of HBAb was observed with disappearance of HBAg from the serum, and in the 2 other patients HBAg persisted once it appeared. In all 3 patients who had HBAg at the time of initiation of chemotherapy, bone marrow suppression was associated with a marked increase in HBAg titer. The increase in HBAg titer was associated with hepatocellular damage, as manifested by an elevation in serum transaminase enzymes. These observations suggest that antitumor chemotherapeutic agents reduce HBAb titers. In some patients, HBAg appears after a decrease in HBAb titers. In patients with preexisting HBAg, such therapy leads to large increases in HBAg titer. Whether this appearance or increase of HBAg is related to an inhibition of antibody formation, allowing expression of preexisting antigen, or to an inhibition of cellular immunity, allowing viral proliferation, is uncertain.


Types of personnel projected to meet the future dental needs of society. There is mounting pressure to re-examine the traditional methods for delivery of dental care. Good health, which includes good oral health, is becoming recognized as a basic right of all people and governments are obliged to subsidize health care in many countries. Part of the cost lies in the training of health professionals in the medical and dental schools. Though  conditions vary in different countries, there is an almost universal shortage of fully trained dentists, and with increasing demand for dental care there is no possibility of producing a sufficient number to meet the need. The profession finds itself overwhelmed by the need for treatment of dental disease and prevention is relatively neglected. It is necessary to determine whether the present methods of delivering dental care are the most efficient in terms of cost, always remembering that dentistry is a personal service and must not be dehumanized. There is ample experience to show that auxiliaries can be trained to undertake a range of tasks to a high standard and with an ethical approach to the patient. A number of such schemes are discussed in detail. Though it is clear that no single pattern will fulfil the needs of each individual country, some form of team dentistry in which the graduate dentist must always be the key member seems likely to be the best way of meeting the future dental health needs of the world.


Fédération Dentaire Internationale chronicle of the 62nd Annual World Dental Congress London, United Kingdom, 8-14th September 1974.


The transplantation and surgical movement of developing teeth. There has now been one hundred years of study, research and clinical application into the possibility of transplantation of tooth germs, and a short review of the literature is given. Two clinical cases are described in which replacement of upper incisors has been successfully achieved by auto transplantation of a developing lower bicuspid and upper canines respectively. Long term follow up of such cases now extends over a decade and it is suggested that this technique has reached a stage now hen it can be recommended to the dental profession generally as a worthwhile clinical approach.


Classification of epidemiologic studies of dental caries and definitions of related terms. Compiled by the Commission on Classification and Statistics for Oral Conditions, FDI.


The utilization of dental skills in non-dental situations. The development of electronic control systems has enabled severely physically handicapped people to revolutionize their lives by using any minimal residual movements they may have to operate micro-switches linking them with typewriters and other environmetal controls. Technical skills of a high order are required in making the unique splint or interface which links the switches with these residual movements whether of the tongue, lips, chin, eyebrow, finger or toe. Through the initiative of the Cordent Trust and generous financial support from the Leverhulme Trust a mobile laboratory was designed and built and a dental technician appointed for a three-year development project in the use of these switches as it was felt that his experience was particularly appropriate to the work and would also demonstrate how dental skills can be used to bring about a degree of rehabilitation far beyond the oral environment.


An improved abrasive enamel microsampling device. An improved enamel abrasive microsampling technique with an electronic preset counter and comparator has been designed. In vivo enamel microsamples were obtained from 30 incisors and premolars. The results showed low coefficients of variations for both enamel fluoride concentrations and depths of microsamples in vivo.


Editorial: Good citizenship?

Editorial: Good citizenship?


Distribution of the dental lamina and deciduous tooth development in the mandible of the domestic pig. Specimens of known age, weight, and crown-rump length were used to characterize the distribution of the dental lamina and deciduous tooth development in the mandible of the domestic pig.


Quantitative microprobe analysis of amalgam. A quantitative microprobe analysis was conducted on three commercial amalgams to determine the nature of the phases present. The presence of tin in the Ag-Hg phase (gamma1) was confirmed and Cu-3Sn was found in the original alloy particles. In the dispersant amalgam studied, little Sn-Hg phase (gamma-2) was found and the reaction phase Cu-6Sn-5 was identified.


Tooth size associations of three morphologic dental traits in a melanesian population. The tooth size associations of incisor shoveling, Carabelli's cusp, and mandibular molar groove pattern were determined for a technologically primitive Melanesian population. Their significance to previously postulated adaptive mechanisms for the morphologic traits is evaluated, as is a possible mode of inheritance for the traits.


Effect of constant currents on orthodontic tooth movement in the cat. Constant 10 muA currents were applied to the mandibles of 12 cats via electrodes implanted mesial and distal to premolars undergoing orthodontic treatment. A third were moved toward the cathode, a third were moved toward the anode, and a third were moved in the absence of an applied field. No significant difference in total movement was seen at the end of five weeks.


Distribution of stresses in porcelain-fused-to-metal and porcelain jacket crowns. An idealized porcelain jacket and porcelain-fused-to-metal crown model was prepared, loaded, and analyzed to establish the trends and distributions of the internal and external stresses. Loads at 30 degrees to the vertical axis created adverse tensile stresses at the level of the gingiva and specifically at the gold-dentin-cement interface.


Penetrativity of sealants: I.

Penetrativity of sealants: I. Penetration coefficients of sealants were measured. It was found that the time required for a sealant to penetrate a specific distance is highly dependent on the penetration coefficient of the sealant.


Effects of cement type and thickness on retention of serrated pins. The retentive capacity of cemented pins was determined. Zinc phosphate, polycarboxylate, and cyanoacrylate were used to cement threaded pins (0.024 inch) into precise channels of 0.025, 0.026, and 0.027 inch. Highest retentive values were realized when zinc phosphate and polycarboxylate cements were used with the smallest pin-channel mismatch. Ethyl cyanoacrylate was least retentive and demonstrated no mismatch dependency.


Dental field theory: an application to primate evolution. A major complicating factor in using dental data in analyses of taxonomic and evolutionary problems is the existence of morphogenetic fields. Efforts are made to abstract tooth crown size morphogenetic fields of the orangutan. The utility of coefficients of variability and factor analysis, to this end, is presented. Resulting morphogenetic dental crown size fields are described and related to hominoid dental evolution.


Size variability within the deciduous dentitions of male and female Macaca nemestrina.


The basic science curriculum: a major problem in dental education.


Editorial: The pass/fail system in dental education.


Solubility and water absorption of orthodontic cements. Solubility and water absorption of eight orthodontic cements were determined as a function of time. Two brands of BIS-GMA and three brands of acrylic cements ranked about equally in solubility and water absorption. Three brands of polycarboxylate cements were appreciably poorer in these properties.


Relationship between dental school performance and preprofessional major courses of study. This study examined the records of dental students in the class of 1969 at the university of Pittsburgh School of Dental Medicine, in an attempt to determine statistically what preprofessional major was the best predictor of academic success in dental school. In the sample studied, no differences were found among the four groups-when they compared on the variable, dental school grade point average. These data suggest that the selection of the preprofessional major course of study may bear little relationship to academic performance in dental school.


Survey of undergraduate endodontic curricula. A survey of undergraduate endodontic curricula in 67 United States and Canadian schools has been carried out. The response rate was 82%, with 2 of the 53 responses being incomplete. The major findings were as follows: 1. There was an extremely wide range in curriculum hours, but the average number of clock hours (46 hours) for the preclinical lecture and laboratory period compared favorably with the minimum recommended in 1965.' 2. The average of about six teeth treated during the clinical period also compared favorably with the minimum recommended in 1965.' 3. The average time required for each clinical case (11 hours per tooth) might suggest a critical reevaluation of teaching methods and philosophy.


Fracture mechanics of dental poly (methyl methacrylate). Strength characteristics of dental poly(methyl methacrylate) were studied in terms of the fracture surface energy and inherent flaw size, using the methods of Berry.2-9 Dental poly(methyl methacrylate) is weaker than the corresponding bulk polymer because the former has a lower energy and higher inherent flaw size.


Early prenatal variability in the order of permanent tooth development.


Massed vs. distributed practice in learning dental psycho-motor skills.


Objective evaluation of quality in cavity preparations. Significant improvements in reliability of criteria measures were obtained by using a newly developed instrument to evaluate objectively the quality of cavity preparations in comparison to subjective ratings by the instructors of the quality of cavity preparations.


Stress relaxation studies on amalgam.

Stress relaxation studies on amalgam.


Wound healing after potassium hydroxide and surgical gingivectomy in rats.


An approach to teaching anatomy.

An approach to teaching anatomy.


The presence of guanosine diphosphofucose: glycoprotein fucosyltransferase in human saliva.


Latency and inhibition of human masticatory muscles following stimuli. Latency-inhibition behavior was always produced in contracting anterior temporal muscles following the application of various stimuli to the teeth and jaws of 31 subjects. Statistically significant differences in duration were generally observed with different procedures. In half of the subjects, the first one or two closures in a sequence of repetitive tapping evoked a longer period of inhibition than subsequent closures. No reflex or latency-inhibition behavior could be produced in contracting digastric muscles. Comparisons of means for individual subjects did not follow the pattern suggested by comparisons of total sample means in almost half of the subjects.


Lipid-dependent calcification of elephant tusk matrix.


Editorial: The high cost of dental education?


Specificity and some physical properties of cathepsin D from bovine uterus and dental pulp. The action of uterine cathepsin D on the insulin A-chain (S-sulfo) and porcine glucagon was compared with the action of bovine dental pulp cathepsin on the same substrates. Differences observed with respect to molecular and catalytic properties suggest that different gene products (coding for the same function) are used during cell differentiation.


Effect of single versus fractionated doses of x-radiation on incisors in rats. This study compares the effect of single vs fractionated doses of X-radiation on the incisor of the rat. The results showed that fractionated doses are more damaging than a single dose and that three fractionated doses have a stronger effect than five.


Instrumental evaluation of mouth odor in a human clinical study. Gas chromatography and a flame photometric detection system measured directly from mouth air the sulfur volatiles associated with malodor. Statistically significant reductions in the hydrogen sulfide and methyl mercaptan levels were observed with use of the test rinse vs a placebo rinse. The method appears potentially useful in objective clinical evaluation of mouth odor.


Letter: Debate on effects of tongue thrust.


Cellular responses to dental amalgam in vitro. Cytotoxicity of fine cut amalgam was persistent until 24 hours after trituration in vitro, whereas cytotoxicity of spherical amalgam diminished more quickly. Increasing mercury content in spherical amalgam increased cytotoxicity. Possible reactions for the diminution of cytotoxicity of amalgams with time are discussed.


Levans: I. Fractionation, solution viscosity, and chemical analysis of levan produced by Streptococcus salivarius. Levan produced by Streptococcus salivarius was fractionated into a series of 20 fractions of varying molecular weight. The range of intrinsic viscosities of the fractions was 0.07 to 0.18 dl/gm in water and 0.20 to 0.29 dl/gm in dimethyl sulfoxide. The molecular weight of the unfractionated leval determined by light scattering was 31.5 times 10-6. Small amounts of fatty acids and protein were found associated with levan.


Effects of oral streptococci on electrophoretic properties of human salivary anionic proteins. Incubation of saliva supernatant after three hours at 37 C revealed that salivary anionic proteins were susceptible to enzymatic attack by salivary enzymes not removable by centrifugation at 10,000 g. In the presence of washed suspensions of S mutans or S sanguis additional changes in electrophoretic behavior of anionic proteins occurred. Differences between organisms suggested a selectivity of attack on the anionic proteins.


The cost of dental education--the challenge and the methods of response.


The need for standard methodologies for determining individual dental school educational costs as a basis for federal support.


Genetic and epidemiologic studies of oral characteristics in Hawaii's schoolchildren: V. Sibling correlations in occlusion traits. Sibling correlations with adjustment for age, sex, and other covariates showed the highest degree of similarity in incisor width, followed by malalignment, overjet, overbite, crowding, spacing, and crossbites. The smallest intrafamily correlations were observed in the variables in buccal segment relationship, especially in neutroclusion and idealized occlusion pattern.


Association between HL-A2 antigen and various periodontal diseases in young adults.


Comments on the Institute of Medicine study of health education costs.


Glucose transport in Streptococcus mutans: preparation of cytoplasmic membranes and characteristics of phosphotransferase activity. Cytoplasmic membranes from Streptococcus mutans were used to study phosphoenolpyruvate (PEP)-dependent glucose transport. The Km values for glucose and PEP were 0.3 and 0.4 mM. The system was sensitive to sulfhydryl reagents and detergents. The nonmetabolizable analogue 2-D-deoxyglucose was readily phosphorylated while alpha-methyl-glucose and 3-0-methylglucose were inefficiently derivatized. The fermentable sugars fructose, galactose, mannitol, and sorbitol were phosphorylated at reduced rates.


Comparison of wet weight of plaque and a plaque index.


Effect of conditioning with fluoride and phosphoric acid on enamel surfaces as evaluated by scanning electron microscopy and fluoride incorporation. The etching effect of 50% H-3PO-4 applied together with 2% NaF or SnF-2 was compared with the effect of H-3PO-4 on pre- and postfluoridated enamel by scanning electron microscopy. Substantial etching of enamel resulted with use of 50% H-3PO-4 with 2% NaF. High fluoride incorporation in the surface provided additional protection of the conditioned enamel.


Stretching the community college dollar.


Reinforced polycarboxylate cements.

Reinforced polycarboxylate cements. Mechanical properties of polycarboxylate cements are greatly improved by incorporation of high modulus fibers such as potassium titanate into acrylic-itaconic acid and acrylic-itaconic-acronitic acid copolymers. Other desirable properties of the cements are not changed by the addition of fibers.


Erosion and fluoride content in molar surfaces of rats that drank a cola beverage with and without fluoride.


The dollar crunch: implications for dental and dental auxiliary education.


Effect of fissure sealants on the prevention and progress of caries in rats.


Mechanical properties of a nonprecious type III alloy.


A survey of resources of continuning education programs in american dental schools.


Students' costs for a dental education in a three-fiscal-year program.


Effects of high altitude and hypophagia on mineral metabolism of rats. Electrolyte excretion and balance were compared in meal-eating, adlibitum-fed rats maintained in Denver (1,600 m) and on Pikes Peak (4,300 m) and in meal-eating rats maintained in Denver but pair-fed to the Pikes Peak animals. Most of the changes in excretion and balance at Pikes Peak were attributable to hypophagia. At both elevations, equivalent decrements in mineral intake led to nearly equivalent decrements in mineral excretion. Comparisons of the Pikes Peak and Denver pair-fed animals, however, revealed certain changes that were unique to high altitude. These included a marked and sustained reduction in ammonia excretion over the 13-day period of exposure. The higher elevation also produced an enhanced sodium excretion on day 1 of exposure and a reduced sodium balance over the first 6 days. Potassium balance showed no changes unique to high altitude during the first 6 days on Pikes Peak but was significantly reduced during week 2 of exposure. The urinary sodium:potassium ratio was elevated during the first 4 days at 4,300 m, but this effect was attributable to altitude on day 1 only. Enhanced calcium and magnesium excretions, relative to those observed in the pair-fed rats, were observed over the middle and latter portions of the exposure period. The balance of these two minerals showed no altitude-dependent effects. Chloride and phosphate excretions showed an altitude-dependent reduction during day 1 and week 1 of exposure, respectively. These changes were associated with more positive balances. It is concluded that the altitude-dependent effects on mineral metabolism are largely, if not entirely, attributable to hypocapnia and associated alkalosis.


Intraoral biopsy of the parotid gland.

Intraoral biopsy of the parotid gland. Although biopsy of the parotid gland is occasionally necessary for diagnostic purposes, surgeons hesitate to perform a biopsy because of the possible adverse effects, such as facial scarring or damage to facial nerves. An intraoral technique was used for biopsy of a parotid gland of a young woman. The procedure was successful; a diagnosis was made and there was no facial scarring. The potential hazards must be weighed against the benefits.


Complications associated with maxillary osteotomies. There are certain complications involved in maxillary ostetomies; devitalization of teeth, loss of part or all of the osteotomized segment, and relapse are possible problems. The paramount cause of the complications in seven different cases seemed to be the interruption of the blood supply to the operative site. A seven-point guideline is formulated; it integrates preoperative planning, surgical procqedures, and postoperative care.


Mandibular atrophy: a theory of its cause and prevention. The unconscious habit of holding the teeth together or clenching, or both, is one of the most dominant factors that leads to  mandibular atrophy. This habit causes long periods of mucoperiosteal ischemia due to denture pressure, with inflammation, a lowered PH, and a net bone loss. Pressure resorption is postulated as the primary cause of mandibular atrophy.


Clinical-pathological conference. Case 11. Part 1.


Lactic acid concentration in various tooth structures in rats maintained on either a cariogenic or noncariogenic diet.


Oronasal fistula following anterior maxillary osteotomy. A complication of oronasal fistula secondary to anterior maxillary osteotomy occurred; it was successfully treated after two attempts at closure.


Experimental gingivitis: development of a new strain of plaque-susceptible rat.


Multiple facial trauma complicated by occlusion of the internal carotid artery. The occurrence of thrombosis of the internal carotid artery is a rare entity. Such a case, in association with multiple facial fractures, has been presented. The management of the patient was complicated by neurological disturbances that affected definitive treatment. This case illustrates the importance of close monitoring of all patients with facial trauma before, during, and after surgery.


Trichinosis associated with oral squamous cell carcinoma: report of three cases. Three patients with oral squamous cell carcinoma had Trichinella larvae in the associated oral soft tissues. Cocarcinogenesis may be involved in the interrelationship between  trichinosis and oral squamous cell carcinoma.


Submandibular duct sialolith of unusual size and shape. An unusual sialoith within Wharton's duct was associated with an abscess of the submandibular space. Previously reported sialoiths of considerable size are reviewed, and etiology, symptomatology, and surgical removal are discussed. Emphasis is placed on the need for thorough examination of patients who have symptoms of sialoithiasis in an attempt to locate the sialolith before it assumes unusual dimensions.


A survey of facial fractures: Bellevue Hospital, 1948-1974.


Letter: Further comments on cardiac arrest from diazepam.


Letter: Legal aspects of splicing radiographs.


Editorial: ABOS--it's responsibility and accountability.


Editorial: The unreasonableness of UCR.

Editorial: The unreasonableness of UCR.


Letter: Frustrations of oral surgery.

Letter: Frustrations of oral surgery.


Letter: Oppisition to board certification.


Bone healing and revascularization after total maxillary osteotomy. Adult rhesus monkeys were used as experimental analogues to investigate vascularization, revascularization, and bone healing associated with total maxillary osteotomy. Microangiographic and histologic studies showed minimal transient vascular ischemia, minimal osteonecrosis, and early osseous union. Transection of the greater palatine arteries had no discernible effect on the circulation to the teeth and bone in  the maxilla and its enveloping soft tissues. The results of experiments in animals and clinical studies indicate that palatal mucosa and labial-buccal gingiva provide an adequate nutrient pedicle for single-stage total maxillary osteotomies.


Reimplantation of freeze-treated mandibular bone. Mandibular bone devitalized by freezing after removal from the body and subsequent reimplantation was observed for its potential to act as a framework of new bone formation. Clinical union and bony replacement occurred when the reimplanted bone was covered by healthy, well-vascularized soft tissue. New bone initially formed subperiosteally along the devitalized bone. Later specimens showed increased production of endosteal bone. The results suggest that a resected mandible subjected to freezing might be immediately reimplanted as a graft when the mandible is involved as part of a radical operative procedure. Further studies are indicated to evaluate this potential when the periosteal covering is removed.


Use of Scialom pins for fracture fixation.


Intraoral junctional nevus: review of the literature and report of case. Pigmented nevi are uncommon in the oral cavity in comparison to their frequency on the skin. The junctional variety is extremely rare; it accounts for approximately 4% of reported intraoral nevi. Another case of intraoral junctional nevus is added to the literature. A review and a discussion of cellular nevi are presented and the realtionship of junctional nevi to malignant melanoma is considered. Regardless of the appearance of the lesion, wide surgical excision is recommended for all pigmented lesions within the oral cavity.


Treatment of temporomandibular joint ankylosis with methyl methacrylate interpositional arthroplasty: reprot of four cases. Four cases of interpositional TMJ anthroplasty are presented. All patients had been operated on previously. The initial success was compromised by reunion of the proximal and distal surgical sites. These failures were due to inadequate gap arthroplasty; lack of complete coverage of the superior distal stump; or lack of retention of the alloplast at the site of placement. The case of manipulation and good tissue tolerance of methyl methracrylate make it an excellent material for interpositional arthroplasty.


Hyperbaric oxygen treatment of mandibular osteomyelitis in osteopetrosis. A patient was successfully treated with hyperbaric oxygen for chronic osteomyelitis of the mandible associated with osteopetrosis. This mode of therapy appears to have a definite place in the management of such patients. There was no clinical, radiographic, or laboratory evidence that the osteopetrosis was made worse by the hyperbaric oxygen.


A "true giant cell tumor" in the mandible?


Cementoblastoma of the maxilla: report of case. A case of cementoblastoma of the maxilla has been presented. The lesion is considered unusual because of its location size, and close association with the cementum of the root of the tooth.


Intraoral use of Kirschner pins.

Intraoral use of Kirschner pins.


Colitis after clindamycin therapy.

Colitis after clindamycin therapy. Colitis developed in a young patient who was receiving clindamycin as part of the management of pericoronitis. Vigorous treatment of the colitis became necessary. The case and the recent literature that has dealt with this potentially very serious complication of lincomycin and clindamycin therapy are reviewed. The dental profession should become aware of this dangerous side effect and exercise caution in prescribing any medication that could produce such a serious outcome.


An investigation of the clinical and histologic effects of selected dentifrices on human palatal mucosa. A study was undertaken in 24 human volunteer subjects to determine the possible effects of selected commercially available dentifrices on clinically normal masticatory mucosa. An acrylic stent was fabricated which was designed to hold four test dentifrices in close apposition to the palatal tissues for 1 hour. Evaluation approximately 8 hours later revealed pathologic responses which were evident clinically and histologically. 1. Clinically, palatal tissues exposed to Crest were not distinguishable from control areas, while Colgate (mfp), MacCleans, and Ultra Brite produced erythematous changes which were statistically significant when compared with adjacent control sites. 2. Histologically, epithelial changes were seen within the test sites which ranged from a parakeratin-like surface layer to necrosis and intraepithelial abcess formation. Control sites consisted of normal orthokeratinized palatal mucosa in all cases. 3. The more severe microscopic reactions were noted with MacCleans and Ultra Brite, while the milder reactions were associated with Colgate (MFP). Crest infrequently produced a parakeratin-like response. The response was not statistically significant when compared with controls. 4. The clinical and histologic reactions were generalized throughout the test population, suggesting that the responses were not due to individual hypersensitivity but due to irritation from one or more of the dentifrice components. Although the clinical significance of these findings could not be readily assessed, the potential for irritation of human palatal mucosa by selected dentifrices has been demonstrated. These findings support the suggestion by the World Workshop in Periodontics (1966)20 that efforts should be directed to the development of dentifrice materials less harsh to the oral tissues.


A long term clinical study evaluating the effect of two dentifrices on oral tissues. 1. A long term (54 months) supervised, double-blind human clinical study has been conducted to ascertain whether the routine use of a commercially available cosmetic dentifrice, with purported stain removal and flavor impact characteristics, would cause adverse manifestations in the oral tissues, as compared to the similar use of a more conventional type of commercially available dentifrice. 2. One hundred and twenty male and female subjects (aged 12 to 70) were randomly assigned to the use of one of the two dentifrices under investigation, after which they used the assigned dentifrices twice daily (1 min each brushing) under supervised conditions for a period of 54 months. 3. Clinical examinations were conducted on all subjects initially (base line), and at 3-month intervals throughout the 54-month course of the study. This examination included a complete and thorough inspection of the oral soft and hard tissues. 4. The results after 54 months of continuous use of the dentifrices (representing a total dentifrice/oral tissues exposure time of approximately 45 hours per subject) indicated that neither of the two dentifrices caused any adverse reactions of the oral soft tissues and that both dentifrice groups had similar patterns and levels of cervical abrasion and/or erosion. 5. The results also indicate a lack of direct correlation between laboratory abrasivity values (as determined by a radioactive dentin abrasion procedure) and the clinical situation, thus suggesting that factors other than dentifrice abrasivity may play an important role with regard to tooth wear.


Primate model for testing periodontal treatment procedures: I. Histologic investigation of localized periodontal pockets produced by orthodontic elastics. Experimental periodontal lesions have been produced in Rhesus monkeys using orthodontic elastics. These lesions are characterized by an irreversible apical positioning of the junctional epithelium and both horizontal and angular bone loss. It was concluded that this lesion is suitable for testing the effect of periodontal treatment.


Delayed hypersensitivity in guinea pig gingiva.


A new semiadjustable articulator. Part II. Adjustment of a new-concept articulator.


A form and function concept of occlusion and the maxillomandibular relationship. A fixed retruded positional concept for the mandible is traceable historically to early dental prosthodontic attempts to obtain duplicable interocclusal records. The original method, derived for relating the maxillary and mandibular jaws for edentulous patients, later gained acceptance as a physiologic entity for patients with teeth as well as for those who were edentulous. Ultimately, static centric relation led to entirely reproducible systems, involving all mandibular movements, which endeavored to match occlusal contacts with a fixed condylar envelope of motion. A fixed or static interpretation of centric relation has become the common touchstone for virtually all the subspecialties of dentistry, regardless of the relative matching and spatial relationships of the jaws,and, as such, misdirects diagnosis and treatment. An attempt has been made to demonstrate that the temporomandibular articulation has a wide range of adaptability as well as a remodeling capacity  and that it assumes its position as a result of the interplay of intercuspation of teeth and the neuromusculature. A dynamic concept of centric relation is presented as a quasifixed position of temporary duration which exists in the form of an equilibrium established by the balance of the neuromusculature and ligaments. The adoption of a dynamic or alterable concept of centric relation allows for diagnosis and treatment which is rationalin theory and workable in fact.


The plaque-retaining capacity of four dental materials.


Leakage around various types of retention pins.


Immediate implantation of acrylic resin teeth into human tooth sockets.


Construction of an acrylic resin articulator mounting platform. A technique is presented for constructing an articulator mounting platform for maxillary casts. It simplifies and standardizes the mounting procedure.


Anteroposterior position of "Myo-Monitor centric". Nine patients had interocclusal recordings made at "Myo-Monitor centric", centric occlusion, and centric relation. With the use of centric relation as a reference point, the anteroposterior distances from centric relation to centric occlusion and Myo-Monitor centric were measured. In addition, the variations in Myo-Monitor centric were analyzed by making repeated interocclusal records on the same patient. Results showed that, within the limits of this study, Myo-Monitor centric was anterior to centric relation but was slightly retrusive to centric occlusion. Also, Myo-Monitor centric recordings were variable from the left and right sides of the same patient and varied on the same side of the same patient.


Morphogenesis of inflammatory papillary hyperplasia.


The effects of variations in the opposing dentition on changes in the partially edentulous mandible. Part II. Densitometric measurements. Distal-extension lower removable partial dentures were used to study the effects of various types of opposing dentitions on the residual mandibular ridge. The opposing-dentition groups included complete upper dentures, removable partial upper dentures, and natural teeth. Changes in the bone of the lower residual ridge were measured by means of densitometry. A significant densitometric difference was found in the bone of the partially edentulous mandible between the group of subjects wearing complete upper dentures and the group with natural upper teeth. The reason for this difference is uncertain; however, several theories can be offered. These are (1) an inherent bone difference between the subjects in the two groups, implying a difference in the bone of the group that retained their natural upper teeth longer than did the complete denture group, (2) an increased frequency and/or duration of muscle pull on the mandible due to clenching of the teeth to stabilize the upper complete denture, and (3) the possibility of coincidence. None of the densitometric changes measured at +18 months was significant.


Clinical evaluation of composite resins as anterior and posterior restorative materials.


Development of a simplified system for clinical evaluation of occlusal interrelationships. Part II. Storage of the information. The development of a simplified system for evaluation of occlusal interrelationships has been discussed in two parts. Part I concerned itself with data obtained from a Patient Questionnaire and through clinical examination. Part II has dealt primarily with the method of transcription of collected information and with data processing keypunch instructions. It is anticipated that this method of data collection will provide the vehicle for an ongoing, broad-base study of occlusal and temporomandibular joint/muscle interrelationships.


Pantographic records on TMJ dysfunction subjects treated with occlusal splints: a progress report. Five subjects with TMJ dysfunction showed difficulty in making reproducible mandibular border movements as recorded by a pantograph. These subjects were treated with occlusal bite splints, and muscle activity was studied by electromyography. After one month of treatment, most subjects showed relief of clinical symptoms and improved EMG muscular activity. Most of the subjects' mandibular movements did not improve to the point of making reproducible border movements on a pantograph. The length of time and the type of treatment may have had a significant effect on the results. This should be investigated further.


Use of in vitro test method as applied to denture surface identification.


Letter: Reproducibility of molded condylar controls with an intraoral registration method. Part I. Simulated movement.


A critical examination of the barriers to the receipt of dental care.


The training and utilization of paraprofessional personnel in a public health dental program of prevention.


The influence of mass media on the public's attitude toward fluoridation of drinking water in New Orleans.


Using optical character recognition to collect data from a program of incremental dental care for children.


Health services for adulthood.

Health services for adulthood.


Contemporary New Zealand issues.

Contemporary New Zealand issues.


Cultural aspects of ageing.

Cultural aspects of ageing.


The primary care role.

The primary care role.


Auckland exercise 'Medaid'.

Auckland exercise 'Medaid'.


The frightening gap.

The frightening gap.


Where success lies.

Where success lies.


But what kind of life?

But what kind of life?


Compulsory, or not?

Compulsory, or not?


Pragmatic axles turn on emptiness.

Pragmatic axles turn on emptiness.


Perinatal care in the United States.

Perinatal care in the United States.


Motor pauses in EMG activity during chewing and biting. Biting on hard particles during chewing sometimes produced motor pauses but more often abrupt atypical terminations of the EMG patterns occurred. A series of tests with different experimental biting and chewing situations were performed. The results indicate that the motor inhibition that occurs during biting and chewing mainly are of two different origins. The inhibition that occurs during tooth tapping and biting on hard particles is caused by tendon and muscle stretching occurring as a result of the mechanical stop of the jaw movement. The inhibition occurring when crushing a brittle bolus has a different origin and occurs before tooth contact and is a form of unloading reflex. The periodontal receptors or surface sensibility appears to be of minor importance for these types of motor inhibition.


Occupational health nursing.

Occupational health nursing.


Mother and child care.

Mother and child care.


Oral manifestations in Urbach--Wiethe disease (lipoglycoproteinosis; lipoid proteinosis; hyalinosis cutis et mucosae). The oral manifestations in 27 patients with Urbach--Wiethe disease (UWD) discovered in Northern Sweden are described. The oral regions most frequently affected are the lips, the back of the tongue, the frenulum of the tongue, the palate and the back wall of the pharynx. The general impression is that older patients usually have more marked manifestations than younger, indicating that the oral lesions may become more severe with increasing age. Histopathologically, the disorder is essentially a microangiopathy in which the walls of small blood vessels are thick and PAS-positive, indicating the presence of glycoproteins. In clinically affected regions there are usually PAS-positive extravascular deposits. In material used of lipid histochemical studies, sudanophil droplets were found in the vessel walls. By staining with osmium tetroxide the osmium is--contrary to previous assumptions--in some way bound to the droplets, but for unknown reasons is not reduced to a coloured product. The binding of osmium was demonstrated by the OTAN (osmium textroxide alpha-naphthylamine) method. The exact significance of this finding awaits further studies. The implications of dental anomalies occurring in UWD are discussed.


Index for need of orthodontic treatment. The demands placed on an index for evaluating the need of orthodontic treatment are described. An index designed by the Swedish Medical Health Board is discussed against the background of the above mentioned demands. A new index for the need of orthodontic treatment is presented. It consists of a morphological part in which essential abnormalities are recorded and allotted points according to their severity. The index also has a functional part in which selected functional disorders of the masticatory system as well as occlusal disharmonies are recorded and allotted points. The reasons are given for the choice of the various features included in the index. Practical instructions for the use of the index are given. The new index for need of orthodontic treatment was tried under clinical conditions in two series of children, aged 6--16 years. The variation between the recordings by the same examiner on two occassions was studied by double determinations. With but few exceptions no systematic errors were found between the double determinations. The precision of the new index for need of treatment was found to be the same as of that given by the Swedish Medical Health Board. No systematic differences were found between recordings made by orthodontists and inexperienced examiners. The accidental error of the method was of the same order for orthodontists as for inexperienced examiners. Comparison of recordings made by four orthodontists showed systematic errors between the recordings of functional but not of morphological deviations. Ranking of the children according to the need of orthodontic treatment as judged with the new index differed from that obtained with the system of the Swedish Medical Health Board. The new index attached more importance to functional deviations. This was the main requirement in the construction of the new index.


Citanest Forte--its use in oral surgery. A clinical evaluation of Citanest Forte (brand of prilocaine HCL) was carried out on 3,000 oral surgery patients to determine the effectiveness and safety of the drug. Citanest Forte has been found to be a useful local anesthetic, and the results of this study would indicate that it can be effectively and safely substituted for other local anesthetic solutions currently in use for all routine oral surgery procedures.


Dermoid cyst of the floor of the mouth. Report of a case. Dermoid cysts of the floor of the mouth comprise aproximately 0.01 per cent of all oral cystic lesions. This case is presented because of its large size, its unusual location, and the difficulty encountered in removing the mass.


Osteogenesis within polyethylene implants at fracture gaps. Sterile 7 mm. polyethylene implants were implanted in standard 6 mm. bilateral midfibular fracture gaps in thirty rats (sixty defects), and six rats were used as controls with identical bilateral midfibular fracture gaps. Clinical, radiologic, and histologic studies at a 12-week interval revealed osteogenesis at internal and external surfaces of implants resulting in bony union; however, gaps without implants resulted in fibrous union and nonunion.


Squamous-cell carcinoma of the floor of the mouth with extensive mandibular involvement. The case of a patient with an extensive squamous-cell carcinoma of the floor of the mouth with erosion of the mandibular bone is presented. The history and initial clinical picture were consistent with either carcinoma with superimposed infection or chronic osteomyelitis with an acute exacerbation. A discussion of diagnosis and treatment of carcinoma of the floor of the mouth follows this case report.


Oral carcinoma in situ.

Oral carcinoma in situ. Oral carcinoma in situ (CIS) as a histopathologic entity was studied in seventy-seven patients to determine the clinical and histologic parameters of the disease. There were forty-nine male and twenty-eight female patients, with 45.1 per cent of the lesions being described clinically as white, 15.9 per cent as red, and 8.5 per cent as a combination of the two. The high-risk sites for CIS were floor of the mouth (23.2 per cent of all lesions), tongue (22.0 per cent), and lips (in males only, 19.5 per cent). Histologically, there was a considerable range of variation in surface keratinization, thickness of epithelium, and certain cytologic alterations. The most consistent of all cytologic changes was loss of orientation of cells. There is no information available concerning possible regression of oral CIS, as is known for CIS of uterine cervix. Furthermore, there is no information concerning the frequency of or the period of transition from oral CIS to invasive carcinoma or whether all oral carcinoma is preceded by CIS. Further studies on this disease are essential.


Patient's medical status--a factor in dental treatment. A review of the medical questionnaires of 4,785 patients seen at Temple University School of Dentistry from March, 1973, through January, 1974, revealed that chronic illnesses affect all ages. The problems and complexities found in our patients are never-ending entities. The dentist must be cognizant of all these medical aberrations so that, where indicated, consultations with other members of the health sciences can be obtained prior to providing definitive treatment. With this knowledge of the patient's medical status and medications being taken, the dental practitioner can now individualize this treatment prescription. The profession must accept this responsiblity, so that the patient can be aided in maintaining and sustaining his general health.


Aspects of the fine anatomy of aphthous stomatitis. Samples of human aphthous stomatitis were studied under the electron microscope. The epithelial cells bordering the ulcer present multivesicular bodies, pinocytotic vesicles, primary lysosomes, digestive vacuoles, and autophagic vacuoles. The golgicomplex is noticeably increased; free ribosomes and rough endoplasmic reticulum are abundant. Crystalline structures are close to the nucleus. One or two paranuclear bodies are in most of the nuclei. A frank cell injury is evident, causing a major activity of the digestive cell system; the origin and formation of lysosomes through r.e.r. and the Golgi system are discussed.


Multiple odontogenic tumors and other anomalies. An autosomal dominantly inherited syndrome. The authors report the occurrence of multiple odontogenic tumors in a father, his two sons, and his daughter. These occurred soon after birth and recurred upon occasion, with imcomplete removal. Associated with the multiple odontomas is esophageal stenosis. The occurrence of hepatopathy of unknown origin and an increased susceptibility to infection appear to be other components in this syndrome. A similar case reported in the literature has been cited. Autosomal dominant inheritance is suggested.


Benign osteoblastoma.

Benign osteoblastoma. The eighth case of a benign osteoblastoma of the jawbones is presented. The tumor showed early recurrence after imcomplete curettage. The tumor-bearing part of the mandible was resected and reconstructed with an autologous bone graft. The histologic features of the entire specimen proved its benighn character. The patient is doing well 2 years after surgical treatment.


Radicular variety of double dens invaginatus. A rare, previously unreported case of radicular variety of double dens invaginatus is presented. The probable mechanism of formation is discussed.


Salivary mucoceles.

Salivary mucoceles. A survey of natural mucoceles revealed that there were two types, namely, extravasation and retention, and that extravasation mucocceles occurred most often in younger patients and in the lower lip, whereas retention mucoceles occurred most often in older patients and elsewhere in the mouth.


Periapical tissue reactions after pulp exposure in rat molars. Apical periodontal lesions were produced in the rat molar by exposing the pulp to the oral environment. The natural history of the undisturbed lesion was studied at time intervals ranging from 2 days to 1 year postoperatively. The earliest reactions were usually inflammatory infiltration at the apex. The severity of the lesions was related to the amount of vital pulp still present in the tooth rather than to the time lapse after exposure. After 1 month most pulps has undergone necrosis and the lesions about the apices which followed showed two main types of reaction. In the case of the suppurative reaction, pus drained along a root surface, destroying the periodontal ligament and interradicular bone until it emerged at the gingival sulcus. The sinus tract could become lined with oral epithelium. In the reparative type of reaction, suppuration was absent or minimal and the apices were surrounded by fibrous connective tissue. The fiber bundles occasionally formed a collagenous scar, but they were usually replaced by cementum and bone with a new periodontal ligament. The width of the periodontium was never restored to its normal dimensions. Secondary destruction of the teeth occurred by fracture of cusps followed by caries which started in the exposed pulp chamber. Despite the predominance of destructive factors, spontaneous repair indicated good healing potential of the apical periodontal tissues.


Oral Kaposi's sarcoma.

Oral Kaposi's sarcoma. A new case of primary oral Kaposi's sarcoma associated with immunosuppressive therapy is presented. The literature related to oral Kaposi's sarcoma is reviewed, and the pathogenesis of this condition is briefly discussed. There is a possiblity that  early lesions of Kaposi's sarcoma may be misadiagnosed clinically and histopathologically as simple pyogenic granulomas.


A study of the focal troughs of three panoramic dental x-ray machines. Part I. The area of sharpness. A comparison of three panoramic x-ray machines revealed that the focal trough of the panorex curved inward in the posterior region, that of the GE-3000 remained straight, and that of the Orthopantomograph flared outward. The panorex was found to have the widest trough in the anterior region; the GE-3000 had the widest trough in the posterior regions.


A determination of the minimum radiopacification necessary for radiographic detection of an aspirated or swallowed object. It was hoped that it might be possible to establish some standard or starting point which could be used by future investigators to judge adequate levels of radiopacity of radiopaque denture-base materials. Aluminum and copper were used to define a suitable radiopacity scale. The scale was represented by two sets of specimens--one of regular outline and uniform thickness, the other of irregular shape and tapering thickness. Radiographs of the chest and abdominal regions of a cadaver were exposed, with the specimens placed on the film side and then on the opposite side of the cadaver. The results showed that it was more difficult to locate the beveled irregular specimens, that there was little difference between the chest and the abdomen with respect to ease of locating the same objects, and that the closer an object is to the film the easier it is to locate. For 95 per cent observability, an object should have a level of radiopacity at least equal to that produced by 0.20 mm. of copper.


Correction of severe open-bite associated with muscular disease. Report of a case. A 14-year-old boy presented with a severe open-bite and arch collapse associated with muscular disease. Multiple osteotomies of the maxilla and mandible with autogenous bone grafting were used for surgical closure of the open-bite. A satisfactory and stable skeletal result was achieved. The patient was then referred for orthodontic therapy to achieve a better dental interdigitation and maintenance of the newly created relationship. In severe cases of open-bite multiple osteotomies of the mandible and maxilla may need to be performed in order to accomplish the desired results. These same results may not be ach ieved by any single surgical procedure. The relationship between severe open-bite and muscle diseases needs to be further established. Once these etiologic factors are known, steps could perhaps be taken to alter the maldevelopment of the facial skeleton. Until this happens, the symptoms are best treated by a combination of surgical and orthodontic intervention.


Reconstruction of the chin in cosmetic surgery (genioplasty).


Intraoral actinomycosis. Report of five cases. Five intraoral presentations of actinomycetes are recorded, in three of which the infection was almost certainly specifically due to the microorganisms. The importance of careful histopathologic examination is underlined, and the failure in some cases to investigate apparently simple infections bacteriologically is highlighted.


Letter: Adenoameloblastoma.

Letter: Adenoameloblastoma.


The healing of surgical defects in alveolar bone produced with ultrasonic instrumentation, chisel, and rotary bur. A histologic comparison of the effects of an ultrasonic instrument, a low-speed rotary cutting bur, and a surgical chisel, all used with water coolant, on the rate of healing of dog alveolar bone was made. After reflection of a mucoperiosteal flap, each instrument was used to produce a 3 by 3 by 2 mm. defect in buccal alveolar bone, 3 mm. apical to the alveolar crest and directly overlying the root structure of the right premolar teeth. Dogs were killed immediately following flap replacement with sutures and 3, 7, 14, 28, 56, and 90 days later. Histologic examination of the surgical areas revealed that the bur produced the smoothest surface. At day 3, specimens prepared with the chisel and the ultrasonic instrument exhibited areas of cellular organization along surfaces with the defect and the formation of osteoid in adjacent marrow spaces. At day 7, osteoblastic activity was most pronounced in specimens prepared with the chisel and least in those prepared with the bur. The subsequent rate of healing in later periods appeared histologically to be the best with the use of the chisel, followed closely by the use of the ultrasonic instrument, and the slowest with the bur, the order of which is consistent with the over-all microscopic evaluation of the effect of the three instruments.


Tuberous sclerosis with gingival lesions. Report of a case. A case of Bourneville-Pringle syndrome with oral manifestations in a 40-year-old woman is described. The oral manifestations of this rare syndrome consist of multiple tumorlike papillomas which are located mainly on the anterior gingivae of the upper jaw. The histologic examination revealed small papillomas.


Gonococcal arthritis of the temporomandibular joint.


Primary malignant melanoma of the oral cavity. The natural history of malignant melanoma of the oral cavity is discussed with reference to the findings of previous writers, and six additional cases are reported. These demonstrate the considerable variations in detail of the course of the disease while confiriming the difficulty of treatment and the inexorable nature of the condition.


Fibrous lesions of the skin and mucous membranes which contain stellate and multinucleated cells. Various fibrous lesions of the skin and mucous membranes share the common histologic feature of stellate and multinucleated fibroblasts. These cells are conspicuous under the light microscope because they contain a well-developed, rough endoplasmic reticulum which, because of its high RNA content, stains basophilic. These characteristic cells are a nearly constant feature of the retrocuspid papilla. They are apparent in about half of the fibrous papules of the nose and abundant in about 1 per cent of irritation fibromas. These lesions most likely represent a nonspecific proliferation of the lamina propria or papillary dermis to various stimuli.


Sclerotic cemental masses of the jaws (so-called chronic sclerosing osteomyelitis, sclerosing osteitis, multiple enostosis, and gigantiform cementoma. A series of thirty-eight cases of densely sclerotic lesions of the jaws was studied. The lesions were all at least 1.5 cm, in diameter. Pain, drainage, or localized expansion of the jaw was present in two thirds of the patients. Thirty-four of the thirty-eight patients were women, and twenty-five were negros. In fourteen instances, a radiographic survey of the entire jaws was available. Thirteen of these fourteen patients had multiple lesions which were usually symmetrically distributed throughout the jaws. In twenty-four patients radiographs of the lesional area only were available for review. In thirty-four of the thirty-eight cases (89 per cent), the sclerotic masses were interpreted as cementum. Although this condition has previously been described as chronic sclerosing osteomyelitis, sclerosing osteitis, multiple enostosis, or gigantiform cementoma, it appears more appropriate to consider these lesions as part of the spectrum of the benign fibro-osseous lesions of periodontal ligament origin. Four of the sclerotic lesions, which were radiographically indistinguishable from the cemental lesions, consisted only of bone. Two of these appeared to be examples of true chronic sclerosing osteomyelitis, and two may be appropriately designated as enostosis or osteomas.


Basal-cell carcinoma of the vermilion mucosa and skin of the lip. In a series of 652 basal-cell carcinomas, twelve were on the upper lip and five were on the lower lip. Three cases of basal-cell carcinoma located on the vermilion mucosa, with only slight involvement of the contiguous skin at the mucocutaneous junction, are reported. Two were on the lower lip and one on the upper lip. The patients were 74, 81, and 81 years of age. All underwent adequate wide local excision. None of the lesions recurred clinically or metastasized over periods of 41 to 80 months.


Dens evaginatus in the Thai. An evaluation of fifty-one cases. Dens evaginatus in the Thai had not been described previously. The incidence of this abnormality was found to be 1.01 per cent. The male to female ratio was 1:1.83, a figure which is comparable to findings among the Chinese, since the two groups are closely related. The evagination was observed in fifty-one patients, with 133 premolars and one molar being affected. Thirty-six premolar showed periapical pathosis which was classified into clinical and radiographic features. The frequency of affection of the different premolars was described, together with the histologic appearances of the anomaly. Pathogenesis of dens evaginatus in the Thai seems to be uniform, determined by racial and genetic factors.


Central pacinian neurofibroma of the maxilla.


A study of the focal troughs of three panoramic dental x-ray machines. Part II. Image dimensions.


Numberous radicular enamel pearls in a premolar of a wild sheep. An unusually large number of enamel pearls were found in a premolar of a wild sheep from Tibet, purported to be the tooth of a Tibetan saint. The enamel pearls show marked preference for the roots.


Radiographic manifestations of a chronic apical rarefying osteitis with an unusual fistulous tract. A case of chronic apical rarefying osteitis in which radiographic examination revealed a circular osteolytic defect extending through the mandible is reported. The defect was well delineated and surrounded by corticated bone, and may have been the result of anatomic or histologic variations of the mandible.


Panoramic roentgen anatomy of the maxillary sinus. A dry maxillozygoma was radiographed with a Panex panoramic unit with lead foil and wires on the anatomic landmarks. The medical border of the maxillary sinus on the pantomogram is seen at the angle of the anterior and medial walls. The lateral border of the maxillary sinus consists of the maximum posterior convexity of the posterior, and medial walls are recognized as anatomic landmarks only when radiopaque materials are attached to individual walls. Most of the anterior and posterior walls of the maxillary sinus are superimposed upon the medial wall in the pantomogram. The anterior wall occupies the lateral third of the maxillary sinus. Anterior, posterior, and medial walls do not appear as anatomic landmarks on the pantomogram.


Genetics.

Genetics.


Xeroderma pigmentosum cells contain low levels of photoreactivating enzyme. Fibroblasts from patients with xeroderma pigmentosum contain low levels of photoreactivating enzyme in comparison to normal cells. Levels vary from 0 (line 1199) to 50 (line 1259) percent of normal. The depressed enzyme levels are not an artifact of low growth rate, age of cell donor, cell culture conditions, assay conditions, the presence of inhibitors, or mycoplasma contamination. We show that human fibroblasts can monomerize pyrimidine dimers in vivo.


Mutations affecting sexual development in Phycomyces blakesleeanus. Although zygospore (mature zygote) formation in P. blakeslleeanus occurs in liquid glucoseglutamate medium, morphological observations are made more easily when cultures are grown on 1-mm-thick agar medium. Zygophores (sexually differentiated hyphae) develop prior to physical contact in crosses of (plus) and (minus) wild types. Zygophores interlock upon contact and then undergo six successive morphological changes to become a zygospore. Mutants with abnormal carotene synthesis exhibit aberrant sexual behavior. Some zygospores do form in crosses of carA mutants and wild types. Only paired zygophores form in crosses of wild type(plus) with car-42(minus), a beta-carotene-accumulating mutant. Zygophores form only on (minus) in crosses of wild type(plus) with carB(minus), carR(minus), carAcarR(minus), and carBcarR(minus) mutants, and only on (plus) in crosses of car-43(plus) with wild type(minus), car-42(minus), and carA(minus) mutants. Zygophores do not form in crosses of car-43(plus) with carB(minus), carR(minus), carAcarR(minus), and carBcarR(minus) mutants. These observations demonstrate that each mating type makes a chemical messenger that stimulates zygophore development in the opposite mating type.


Mitogenic activity of blood components. I. Thrombin and prothrombin. When added to a culture medium of resting confluent chick embryo fibroblasts in the absence of serum, thrombin (EC 3.4.21.5) is able to stimulate DNA synthesis 12 hr later and to cause a substantial increase in cell number over a period of 4 days. As compared to thrombin, prothrombin exhibits low mitogenic activity. However, in the presence of purified Factor Xa (EC 3.4.21.6) and Factor V, prothrombin is converted to thrombin by "thromboplastin activity" supplied by the fibroblasts. Prothrombin, either purified or as a constituent of plasma or serum, may thus be considered to be a reservoir of mitogenic activity in tissue culture unless antithrombin is present in the culture medium in amounts sufficient to neutralize the thrombin formed. By use of a specific inhibitor of proteases, and by separation of prothrombin by absorption on BaSO4, we estimate that the potential mitogenic activity of prothrombin is approximately 30-50% of the total activity that can be obtained by treatment of fibrinogen-free plasma with thromboplastin. In addition to its mitogenic activity, thrombin can also stimulate the migration of cells. These experiments with thrombin illustrate that well-characterized proteases of blood can act as potent mitogens and suggest that they may play a role in the process of wound healing.